feat(effects): add provideEffects function

modules/effects/spec/effects_root_module.spec.ts

@@ -2,7 +2,7 @@ import { TestBed } from '@angular/core/testing';
 import { INIT, Store, StoreModule } from '@ngrx/store';
 
 import { EffectsModule } from '../src/effects_module';
-import { ROOT_EFFECTS_INIT } from '../src/effects_root_module';
+import { ROOT_EFFECTS_INIT } from '../src/effects_actions';
 
 describe('Effects Root Module', () => {
   const foo = 'foo';

modules/effects/src/actions.ts

@@ -8,7 +8,7 @@ import {
 import { Observable, OperatorFunction, Operator } from 'rxjs';
 import { filter } from 'rxjs/operators';
 
-@Injectable()
+@Injectable({ providedIn: 'root' })
 export class Actions<V = Action> extends Observable<V> {
   constructor(@Inject(ScannedActionsSubject) source?: Observable<V>) {
     super();

modules/effects/src/effect_sources.ts

@@ -29,7 +29,7 @@ import {
 import { EFFECTS_ERROR_HANDLER } from './tokens';
 import { getSourceForInstance, ObservableNotification } from './utils';
 
-@Injectable()
+@Injectable({ providedIn: 'root' })
 export class EffectSources extends Subject<any> {
   constructor(
     private errorHandler: ErrorHandler,

modules/effects/src/effects_actions.ts

@@ -0,0 +1,4 @@
+import { createAction } from '@ngrx/store';
+
+export const ROOT_EFFECTS_INIT = '@ngrx/effects/init';
+export const rootEffectsInit = createAction(ROOT_EFFECTS_INIT);

modules/effects/src/effects_module.ts

@@ -7,17 +7,13 @@ import {
   SkipSelf,
   Type,
 } from '@angular/core';
-import { Actions } from './actions';
-import { EffectSources } from './effect_sources';
 import { EffectsFeatureModule } from './effects_feature_module';
-import { defaultEffectsErrorHandler } from './effects_error_handler';
 import { EffectsRootModule } from './effects_root_module';
 import { EffectsRunner } from './effects_runner';
 import {
   _FEATURE_EFFECTS,
   _ROOT_EFFECTS,
   _ROOT_EFFECTS_GUARD,
-  EFFECTS_ERROR_HANDLER,
   FEATURE_EFFECTS,
   ROOT_EFFECTS,
   USER_PROVIDED_EFFECTS,
@@ -58,13 +54,6 @@ export class EffectsModule {
     return {
       ngModule: EffectsRootModule,
       providers: [
-        {
-          provide: EFFECTS_ERROR_HANDLER,
-          useValue: defaultEffectsErrorHandler,
-        },
-        EffectsRunner,
-        EffectSources,
-        Actions,
         rootEffects,
         {
           provide: _ROOT_EFFECTS,

modules/effects/src/effects_root_module.ts

@@ -1,17 +1,9 @@
 import { NgModule, Inject, Optional } from '@angular/core';
-import {
-  createAction,
-  StoreModule,
-  Store,
-  StoreRootModule,
-  StoreFeatureModule,
-} from '@ngrx/store';
+import { Store, StoreRootModule, StoreFeatureModule } from '@ngrx/store';
 import { EffectsRunner } from './effects_runner';
 import { EffectSources } from './effect_sources';
 import { ROOT_EFFECTS, _ROOT_EFFECTS_GUARD } from './tokens';
-
-export const ROOT_EFFECTS_INIT = '@ngrx/effects/init';
-export const rootEffectsInit = createAction(ROOT_EFFECTS_INIT);
+import { ROOT_EFFECTS_INIT } from './effects_actions';
 
 @NgModule({})
 export class EffectsRootModule {

modules/effects/src/effects_runner.ts

@@ -4,10 +4,14 @@ import { Subscription } from 'rxjs';
 
 import { EffectSources } from './effect_sources';
 
-@Injectable()
+@Injectable({ providedIn: 'root' })
 export class EffectsRunner implements OnDestroy {
   private effectsSubscription: Subscription | null = null;
 
+  get isStarted(): boolean {
+    return !!this.effectsSubscription;
+  }
+
   constructor(
     private effectSources: EffectSources,
     private store: Store<any>

modules/effects/src/index.ts

@@ -11,14 +11,11 @@ export { EffectsMetadata, CreateEffectMetadata } from './models';
 export { Actions, ofType } from './actions';
 export { EffectsModule } from './effects_module';
 export { EffectSources } from './effect_sources';
+export { ROOT_EFFECTS_INIT, rootEffectsInit } from './effects_actions';
 export { EffectsRunner } from './effects_runner';
 export { EffectNotification } from './effect_notification';
 export { EffectsFeatureModule } from './effects_feature_module';
-export {
-  ROOT_EFFECTS_INIT,
-  rootEffectsInit,
-  EffectsRootModule,
-} from './effects_root_module';
+export { EffectsRootModule } from './effects_root_module';
 export { EFFECTS_ERROR_HANDLER } from './tokens';
 export { act } from './act';
 export {
@@ -28,3 +25,4 @@ export {
 } from './lifecycle_hooks';
 export { USER_PROVIDED_EFFECTS } from './tokens';
 export { concatLatestFrom } from './concat_latest_from';
+export { provideEffects } from './provide_effects';

modules/effects/src/provide_effects.ts

@@ -0,0 +1,64 @@
+import { ENVIRONMENT_INITIALIZER, inject, Provider, Type } from '@angular/core';
+import { Store } from '@ngrx/store';
+import { EffectsRunner } from './effects_runner';
+import { EffectSources } from './effect_sources';
+import { rootEffectsInit as effectsInit } from './effects_actions';
+
+/**
+ * Runs provided effects. Can be called at the root or feature level.
+ * Unlike the `StoreModule.forRoot` method, this function does not need
+ * to be called at the root level if there are no root effects.
+ *
+ * @usageNotes
+ *
+ * ### Providing root effects
+ *
+ * ```ts
+ * bootstrapApplication(AppComponent, {
+ *   providers: [provideEffects([RouterEffects])],
+ * });
+ * ```
+ *
+ * ### Providing feature effects
+ *
+ * ```ts
+ * const booksRoutes: Route[] = [
+ *   {
+ *     path: '',
+ *     providers: [provideEffects([BooksApiEffects])],
+ *     children: [
+ *       { path: '', component: BookListComponent },
+ *       { path: ':id', component: BookDetailsComponent },
+ *     ],
+ *   },
+ * ];
+ * ```
+ */
+export function provideEffects(effects: Type<unknown>[]): Provider[] {
+  return [
+    effects,
+    {
+      provide: ENVIRONMENT_INITIALIZER,
+      multi: true,
+      useValue: () => {
+        const effectsRunner = inject(EffectsRunner);
+        const effectSources = inject(EffectSources);
+        const shouldInitEffects = !effectsRunner.isStarted;
+
+        if (shouldInitEffects) {
+          effectsRunner.start();
+        }
+
+        for (const effectsClass of effects) {
+          const effectsInstance = inject(effectsClass);
+          effectSources.addEffects(effectsInstance);
+        }
+
+        if (shouldInitEffects) {
+          const store = inject(Store);
+          store.dispatch(effectsInit());
+        }
+      },
+    },
+  ];
+}

modules/effects/src/tokens.ts

@@ -1,5 +1,8 @@
 import { InjectionToken, Type } from '@angular/core';
-import { EffectsErrorHandler } from './effects_error_handler';
+import {
+  defaultEffectsErrorHandler,
+  EffectsErrorHandler,
+} from './effects_error_handler';
 
 export const _ROOT_EFFECTS_GUARD = new InjectionToken<void>(
   '@ngrx/effects Internal Root Guard'
@@ -20,5 +23,6 @@ export const FEATURE_EFFECTS = new InjectionToken<any[][]>(
   '@ngrx/effects Feature Effects'
 );
 export const EFFECTS_ERROR_HANDLER = new InjectionToken<EffectsErrorHandler>(
-  '@ngrx/effects Effects Error Handler'
+  '@ngrx/effects Effects Error Handler',
+  { providedIn: 'root', factory: () => defaultEffectsErrorHandler }
 );

modules/store/src/scanned_actions_subject.ts

@@ -3,7 +3,7 @@ import { Subject } from 'rxjs';
 
 import { Action } from './models';
 
-@Injectable()
+@Injectable({ providedIn: 'root' })
 export class ScannedActionsSubject
   extends Subject<Action>
   implements OnDestroy